He was married on 16th August 1886 to Eliza Mary Rose Veal. Together they had five children. His eldest daughter Rosina's husband was Walter Hurst (also a fireman on board).

In 1912 Mintram had just been released from prison (he had been found guilty of accidentally killing his wife while drunk - relatives say he was drunk and actually trying to stab someone else but his wife tried to intervene and ended up taking the blade).

William Mintram and Walter Hurst met each other shortly before the Titanic went down. William had found a lifejacket, but Hurst had not, so William gave his lifejacket to his son-in-law. This may have contributed to the fact that Walter was able to stay on collapsible B, and to survive, while William did not.